The largest baseball crowd in the history of the Astrodome, 54,037, saw the Reds win their sixth straight game and send Houston to its third loss in a row.

Cincinnati had not been in first place since Aug. 19 when it was tied with the Astros. Houston took over the lead the next day.

Despite the defeat, the Astros held their 11/2-game lead over New York for the wild-card spot. The Mets lost to Atlanta 9-3.

Harnisch (15-10) helped the Reds improve to 5-0 at the Astrodome this season. Cincinnati leads the season series 9-3 going into Wednesday night's wrapup, which matches Steve Parris against Houston's Mike Hampton.

Harnisch allowed four hits and moved to 4-0 against his former team this year. He struck out three and walked none.

Scott Williamson pitched the ninth for his 19th save.

Sean Casey hit his 25th homer in the first, and the Reds added two more runs in the second against Lima (20-10) on singles by Eddie Taubensee and Pokey Reese.

Lima was in trouble again in the third. Taubensee's infield hit scored Barry Larkin for a 4-1 lead with two out. Lima walked Bret Boone to load the bases but Reese grounded out.

Lima lost his third straight decision since getting his 20th victory Sept. 11 against the Chicago Cubs. Lima went six innings, allowing four runs three earned and eight hits with eight strikeouts.

Craig Biggio hit a leadoff single in the Houston first, and Harnisch retired the next 12 batters. Biggio, however, scored on Jeff Bagwell's grounder.